On April 29, 1996, the Data Safety and Monitoring Committee recommended that enrollment be closed based on an interim analysis of 207 randomized patients which indicated that the primary outcome, 20% reduction in death or ECMO among patients receiving nitric oxide, had been met without evidence of toxicity. The congenital diaphragmatic hernia pilot showed no apparent benefit from nitric oxide. Follow-up evaluation at 18 months of age will be complete in early 1998. The protocol has been modified to open label inhaled nitric oxide under the NICHD revised protocol IND. Baseline, safety, outcome and 18 month follow-up data is collected on these patients.